Transfer of perfluorooctanesulfonate (PFOS), decabrominated diphenyl ether (BDE-209) and Dechlorane Plus (DP) from biosolid-amended soils to leachate and runoff water

Abstract

Environmental contextThe potential of pollutants to migrate from biosolids must be considered when assessing the environmental risk associated with the application of biosolids in agriculture. We conducted semi-field tests simulating natural conditions to determine the leaching and runoff capacity of emerging organic contaminants following fortification and application of municipal biosolids. We demonstrate the transfer of pollutants from biosolid-amended soil to leachate and runoff water generated by natural rainfall. AbstractAnthropogenic perfluoroalkyl substances, PFASs, and halogenated flame retardants, HFRs, have been detected in different environmental compartments. In order to determine the fate of these compounds in the soil–water system, a semi-field simulated runoff experiment was conducted following the application of municipal organic waste. Therefore, the application of four biosolids was carried out. The biosolids were fortified with perfluorooctanesulfonate (PFOS; ~1 mg PFOS per kg biosolid), decabromodiphenyl ether (c-decaBDE; ~10 mg kg−1) and Dechlorane Plus (DP; ~0.26 mg kg−1) commercial mixtures and were applied to soil packed in 15 runoff-leaching trays (2.5 × 2 × 0.05 m). These trays were designed to collect the leachate and runoff water generated by natural rainfall. PFASs and HFRs were detected in leachate and runoff water from several rainfall events from November 2011 to May 2012 (a first rainfall event of 10.5 × 10−3 m, a second event of 16.0 × 10−3 m and a third pool event with a cumulative amount of 113.1 × 10−3 m) occurring after the initial biosolid application. The total mass distribution calculated in water samples showed a higher content in runoff samples (PFOS, 91 ± 2 %; BDE-209, 76 ± 17 %; DP, 83 ± 14 %). The order of the loamy sand soil affinity for PFOS, BDE-209 and DP was as follows: PFOS < BDE-209 ≤ DP, which was predicted, either from the compounds’ water solubility, the octanol-water partition coefficient (Kow) or the organic carbon-water partition coefficient (Koc). The calculated leaching potential (Lp) index or the Groundwater Ubiquity Score (GUS), which are based on these Kocs, revealed the reverse order of potential transport to surface and groundwater respectively.